The compounds of formula Ia or Ib are valuable intermediate products for the manufacture of compounds which are pharmaceutically active as adenosine A2a receptor antagonist or metabotropic Glutamate receptor 2 antagonist. They are important in the regulation of many aspects of cellular metabolism and in the modulation of different central nervous system activities (WO 01/97786, WO 03/043636, and WO 02/083665).